Access control systems of various kinds are known in the art. Some access control systems serve to provide automated (and/or remote) control with respect to a locking mechanism. Other access control systems provide automated (and/or remote) control with respect to a movement of a movable barrier (such as, but not limited to, a single-piece or segmented garage door, a sliding or pivoting gate, a pivoting guard arm, rolling shutters, and the like). These and other access control systems generally serve to provide some point of control with respect to a mechanism that itself governs, in some fashion, access to some further destination (such as, but not limited to, an apartment complex, a parking area, a business area, a recreation or exercise area, and so forth).
Many such access control systems provide one or more user interfaces. A user can then interact in some predetermined manner with such an interface to effect some desired action on the part of the access control system. For example, such a user may assert an “open” or “close” button, insert an identification card having identifying and/or authorizing information stored thereon into a card reader, or bring a so-called radio frequency identification card or tag having similar information within reading range of a corresponding reader, to name but a few. In many instances such a user interface will be directly coupled to a host access control unit via, for example, an electrical or optical conductor.
Such direct coupling serves well under many operating conditions and circumstances. On the other hand, many times such a direct coupling presents difficulties. For example, there may be physical obstacles (such as but not limited to paved driveways, landscaping, buildings, sheer distance, and so forth) or legal obstacles (such as a lack of a proper right-of-way or easement) that render such an approach burdensome or unfeasible. Wireless solutions have been proposed to meet such needs. By this approach, a wireless link serves in lieu of the direct coupling to bear necessary communications and/or signaling as between a remote user interface and a host access control unit.
Such a solution, however, gives rise to new problems. In many cases the wireless link will, of necessity (due to, for example, legal or regulatory requirements) comprise a relatively low power link. That is, only relatively low powered transmissions may be used to establish the wireless link. Also in many cases, the local operating environment may be relatively inhospitable to radio frequency transmissions. For example, local terrain and/or objects may act as radio frequency energy absorbers or reflectors. This, in turn, can result in sufficient signal attenuation and/or other phenomena (such as multipath distortion) as to render the transmissions unintelligible or undetectable and therefore unsuitable for the intended purpose.
These and other problems can result in an ineffective installation and subsequent operation of a remotely located user input device for an access control system. This, in turn, can necessitate additional installation attention and resources and/or follow-up services that can adversely impact the user's system experience while increasing the costs of installation to the user and/or the installer.
Skilled artisans will appreciate that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale. For example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help to improve understanding of various embodiments of the present invention. Also, common but well-understood elements that are useful or necessary in a commercially feasible embodiment are often not depicted in order to facilitate a less obstructed view of these various embodiments of the present invention. It will also be understood that the terms and expressions used herein have the ordinary meaning as is usually accorded to such terms and expressions by those skilled in the corresponding respective areas of inquiry and study except where other specific meanings have otherwise been set forth herein.